Molecular dielectrophoresis of bio-polymers

Dielectrophoresis (DEP) has found wide applications in manipulations of micron-sized particles such as cells. The authors used a fluid integrated circuit (FIC) concept to fabricate micron-sized electrodes, with which a very high intensity high-frequency field, over 1×10⁶ V/m at 1 kHz to 10 MHz, was created in the steady state. The observation of molecular DEP using Avidin and other biopolymers showed that DEP occurs at field strengths of 0.4-1.0×10⁶ V/m, which is substantially lower than DEP theory predicts. As applications of the molecular DEP, a molecular patterning method and dielectrophoretic chromatography are proposed. In the latter, a biopolymer solution is allowed to flow through a high-intensity field region created in a FIC, and the difference in DEP attraction is used to analyze and/or separate the polymer